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-`JAMES,.-DU'FF, or PEonrA-ILLINo1s.

Letters Patent No. 78,867, dated June 16, 1868.

IMPROVEMENT IN DROP-PRESSES.

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'Be it known that I, JAMVES DUFF, 'of Peoria, in thecounty ofPeoria.,`in the State ot' Illinois, have invented a new and usefulImprovement on Drop-Presses or Drop-Hammer; and I do hereby declare thatthe following isa full, clear, and exact description of the constructionand operation of the same, reference being had to the' annexed drawings,making part of this specification, in whieh- Figure l is a perspectiveview.

Figure 2 is an elevation of the two hammers, vshowing a section of theair-chamber.

' Figure '3 is an end view of the t-wo hammers.

Figure 4 is a plan of the upper hammer.

Figure 5 is a plan of Ythe lower hammer. Y

Figure 6 is a perspective viewof the upper hammer', showing theair-chamber; and

.Figure 7 is a perspective view of the Vlower hammer, showing `theplunger.

The'nature of my invention consists in providing a drop-press ordrop-hammer with a secondary or followinghammer, and a cushion betweenthe two hammers, or -its equivalent, so arranged as toprevent'tlie'rebound. I

I construct my 4drop-press in any of the known forms, Land' applythereto theusual appendages and machinery for working the same; but inorder; to obviate the rebound of the hammer when it strikes, I connectwith the hammer A, a following-hammer, B, bymeans of studpins e e, o'rany convenient arrangement whereby the two hammers, when suspended, willseparate to the requred'extennand the fol1owinghainmeuB rest upon thelower hammer A, when both rest upon the anvil.

I make an airehamber, 6, of any form and size, in the face ofonc of thehammers, and provide thc same with an air-passage and stop-cock, d. l A

`represents a plunger, attached to the contiguous face of the otherhammer, corresponding in. size and form to the air-chamber b. v

The hammers, being at rest upon the anvil, the plunger aoccupies theairchamber b, but, on being raised,

-they separate, and the airfchamber becomes filled with air. When tirehammers drop, the compressed nir, escaping slowly through the stop-cockd, partially sustains the following-hammer B, and itgradually comes torest upon the lower hammer A, producing a constant pressure upon thesame during thel continuance of the blow, and thereby preventing therebound. l

What I claim as my invention, and-desire to secure by Letters Patent,is- The following-hammer B, airchamber b, air-passage and stop-cock d,and plunger a, in combination with thehammer A, when arranged in themanner and operating as and for the purpose herein described.

JAMES DUFF.

Witnesses:

E. B. Pinnen, J. S. STEVENS.

